Author Topic: Power supply  (Read 6294 times)

G8B4Life

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Re: Power supply
« Reply #15 on: September 01, 2016, 11:16:36 PM »
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May I presume that all this great information is for layouts that are RailPro only.

Correct. I think we could go further and say it is for layouts that are DC based but I don't know of any analogue/conventional control DC layouts that use 2 or more parallel power supplies.

DCC boosters, as with the PWR-56 are made to be worked together (power districts) and one would presume that all the required wizardry to prevent the conditions Alan describes are present in the DCC booster. It's probably different for DCC being square wave AC (Alan will most likely know) but I'm sure the principals are the same and that the relevant precautions would have been taken in the design of the boosters.

- Tim



Alan

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Re: Power supply
« Reply #16 on: September 02, 2016, 08:15:06 PM »
By the fact that Ring specifically shows in the manual paralleled PWR56s, we can assume the little gizmo that comes with the power brick has protection built in. Likely the same schottky diode solution mentioned earlier as this arrangement is nearly universal and frequently used. The recommendation to space the PWR56s away from the rail gap is good advice.

Tim is correct about my recommendation applying to non-Ring power supplies. Sorry Bill, but I can't understand why someone would buy a $120 PWR56 when a $19 power supply will run trains just fine. And the bit about a PWR56 regulating the voltage to +-3% is a feature with no benefit. On a layout of any decent size the resistance in the track and bus wiring will cause more voltage deviation than the power supply regulation spec. Besides, 3% is not uncommon. My eBay power supplies regulate that well too not that it matters. How do I know?

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Alan

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When I was a kid... no wait, I still do that. HO, 28x32, double deck, 1969, RailPro

William Brillinger

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Re: Power supply
« Reply #17 on: September 02, 2016, 08:38:34 PM »
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Sorry Bill, but I can't understand why someone would buy a $120 PWR56 when a $19 power supply will run trains just fine.

I don't know why anyone would pay $120 either. It's only $91.96 with shipping on PDC.CA ;)

However I can think of a few reasons to choose the PWR56:
- fault reporting and control integration of the PWR56 with the HC
- repeater function (handy on larger layouts)
- simplicity of wiring (no extra monitors needed)

...and when purchased with an HC the pricing is not bad; it comes with an HC for only $69 in the RPK1 set. 
Odds are if your layout is big enough to need to PWR56's then you'll want at least 2 HC's anyway.
- Bill Brillinger, RPUG Admin

Modeling the BNML in HO Scale, owner of Precision Design Co., and RailPro Dealer.


Alan

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Re: Power supply
« Reply #18 on: September 02, 2016, 10:39:54 PM »
$91.96 Now that's more like it.  ;D

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However I can think of a few reasons to choose the PWR56:
- fault reporting and control integration of the PWR56 with the HC
- repeater function (handy on larger layouts)
- simplicity of wiring (no extra monitors needed)

If I'm not mistaken the PWR56 integration (ability to the power on/off) is for the gizmo, not the actual power supply brick. Even though there is no power going to the track when the PWR56 is turned off, the brick is still running. One has to ask why a remote control on/off button if it doesn't really turn the power supply on/off? And do I really need to know the temperature? All power supplies have integrated over-temp shutdown. The lawyers see to that. A device that catches fire is bad for business. Just ask Samsung right now about their Note 7 recall. For fault reporting a simple LED across the bus does the job just fine. One can put a lot of LEDs on the fascia panel for $100.00.  ;)

Repeater - yeah I understand that. Range has not been an issue fro me. My HC works from the other side of the basement 70' from the train room. But I imagine it is a different story in a busy radio environment like a show or apartment complex. I'll give you that one.

Voltage monitoring on a RailPro layout is absurdly easy. A $2.00 panel voltmeter does the job. It is a tie score on simplicity - Ring 2, Generic 2. PWR56 & brick compared to eBay PS and voltmeter. If you count actual number of wire connections needed then generic wins - Ring 7, Generic 6.

Ring had to offer a power supply to make his product a complete system. I get that. The off-the-shelf generic laptop brick he uses probably is sloppy on the voltage regulation as most bricks are. Bricks also are not suitable for a multiple power supply setup and Tim had to expect modelers to ask for such. So it makes sense he also supplies his gizmo interface which is no doubt a precision voltage regulator. That's why it gets hot and he is concerned about the mounting position. The radio communication is his trademark market differentiation so it too makes sense he includes it.

I am not saying anything bad about the PWR56. I am a delighted RailPro customer. Just making the point that for frugal folk such as myself there is a lot of money to be saved when it comes to power supplies. Money I can spend elsewhere on the layout.

 
Alan

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When I was a kid... no wait, I still do that. HO, 28x32, double deck, 1969, RailPro

William Brillinger

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Re: Power supply
« Reply #19 on: September 02, 2016, 10:50:21 PM »
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Just making the point that for frugal folk such as myself there is a lot of money to be saved when it comes to power supplies. Money I can spend elsewhere on the layout.

Absolutely True.
- Bill Brillinger, RPUG Admin

Modeling the BNML in HO Scale, owner of Precision Design Co., and RailPro Dealer.


G8B4Life

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Re: Power supply
« Reply #20 on: September 03, 2016, 11:29:26 AM »
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Just making the point that for frugal folk such as myself there is a lot of money to be saved when it comes to power supplies. Money I can spend elsewhere on the layout.

You don't have to be frugal, just informed. Ring doesn't exactly go around stating that you can use any power supply that outputs ~14volts but quite purposefully goes about promoting their power supply as the only suitable and RE endorsed supply for their system. Nothing wrong with that, that's good business sense to promote your own stuff but it probably does leave most just going with the RE supply than investigating other options. Even I was not 100% sure until I had the thing in my hands.

I also would imagine the number of PWR-56's sold in the starter kits would far outnumber the number of PWR-56's sold separately. This brings us back to the point you made about a complete system, I don't think many, if any modellers would normally have a suitable power supply just laying around so the inclusion of one in a starter kit is a great way of getting going. That's how I did it. Now I have a large 15v 20 something amp SMPS (price was good) which I can break down into separate districts easily enough if needed and the PWR-56 can be used on a test bench.

Another way to look at it (I don't know if RE does or does not look at it this way) is if your trying to lure folk over from DCC you might try to capitalise on the mindset they might have, that being they need an expensive booster for every power district in DCC so if the mindset has set in and they don't think too hard they might just think they need an expensive PWR-56 for each district too.

I think if people needed the repeater functionality but wanted to use their own power supply it would be great if Ring sold the PWR-56 part (the brick is PA-2) separately but I don't see that happening, limitation of liability etc.

- Tim

Alan

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Re: Power supply
« Reply #21 on: September 03, 2016, 11:58:25 AM »
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need an expensive booster for every power district in DCC

Is that really true? I thought you only had to add DCC circuit breaker units for each power district.
Alan

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When I was a kid... no wait, I still do that. HO, 28x32, double deck, 1969, RailPro

Dean

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Re: Power supply
« Reply #22 on: September 03, 2016, 01:18:30 PM »
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need an expensive booster for every power district in DCC

Is that really true? I thought you only had to add DCC circuit breaker units for each power district.

Yes that's true. If wanted to split my layout into two sections, I would have buy another booster and power supply and run communication cabling back to the main booster. Throw in some circuit breakers and it starts to get expensive.
What I like about the PWR-56 is the fact that you can kill all the power to the track from any place around the layout. I could have used that feature on a couple of occasions.    :-[
Dean

Alan

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Re: Power supply
« Reply #23 on: September 03, 2016, 04:36:11 PM »
WOW! Ring really needs to advertise that on the web site.
Alan

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When I was a kid... no wait, I still do that. HO, 28x32, double deck, 1969, RailPro

G8B4Life

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Re: Power supply
« Reply #24 on: September 04, 2016, 03:00:23 AM »
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Is that really true? I thought you only had to add DCC circuit breaker units for each power district.

Yes and no. Circuit breakers can be used to make power districts, but the typical electronic DCC circuit breakers that are most useful for that purpose I believe are a relatively modern (in the age of DCC itself) development. Before that you used light bulbs (ugh!) or another booster.

The diagram in this article (tonystrains.com/download/MRR-PowerDist.pdf) shows a most likely setup for an informed DCC user today. A user from 10 years ago or an uninformed user of today might have each one of those breakers saying Booster instead. There is a lot of literature around that teaches "except for all but the smallest layouts if you want to run a lot of trains at once, or a number of sound ones break up your layout into districts with smaller capacity boosters rather than using 1 big booster for the whole layout". This is the mindset I talked about.

Going back to the article, our advantage is we can buy a single supply relatively cheap that totals all those boosters and split off from that using breakers (also cheap thanks to it being DC) for our districts. If we need another supply, well that's cheap too. With DCC most small scale boosters are 3 or 5 amp so once your approaching the limit of a single booster (as a heavy yard or engine terminal theoretically could) you need another expensive booster (or more) for other parts of the railroad, or replace with a large really expensive booster - if it's suitable for small scale decoders that is.

- Tim

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Re: Power supply
« Reply #25 on: September 05, 2016, 02:10:03 PM »

...and when purchased with an HC the pricing is not bad; it comes with an HC for only $69 in the RPK1 set. 
Odds are if your layout is big enough to need to PWR56's then you'll want at least 2 HC's anyway.

That's a very good way to get another power supply, I never thought of just getting 2 starter kits, I planned on getting 2 throttles anyway!